On Wed, 3 Aug 2005, Alex Williamson wrote: > Ok, I can see the scenario where that could produce jitter. However, > that implies than any exit through that path could produce jitter as it > is. For instance:
Well what is the difference of this approach from booting with "nojitter"? The ITC offsets are fixed right? Just check that the ITC difference is less than what you want to risk and switch on "nojitter" during bootup if less than the limit. Same effect without changes to the critical timer code patchs. The main problem occurs as far as I know when execution continues on another processor during time measurement. In that case you may get an earlier time later because the ITC of the processor you migrated to is not there yet.... Similar issues may occur if time information is communicated between threads running on different processor. You have an awful nest of rats here so if you do this then please at least do a printk that warns people of what is going on. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
